title: Effect of aging on formation of reactive oxygen species by mitochondria of rat heart.
abstract: Mitochondrial electron transport chain is thought to be a major source of reactive oxygen species (ROS) during aging. However, this view is supported mainly by accumulation of mitochondrial oxidative damage with age and the exact sites of ROS formation remains unknown. In the present study, we measured rate of ROS formation using 2',7'-dichlorofluorescein (DCF) probe in cardiac mitochondria from adult (6-month-old), old (15-month-old) and senescent (26-month-old) rats. In mitochondria oxidizing complex II substrate, succinate, the rate of ROS formation progressively increased with age. In the presence of complex I inhibitor rotenone or complex III inhibitor antimycin A, the rate ROS formation significantly decreased, but even the combination of inhibitors could not fully prevent generation of ROS. Age-dependent increase of ROS formation was accompanied by a loss of thiol groups, tryptophan degradation and increased lipid peroxidation. These data suggest that in addition to complex I and complex II other mitochondrial sites can contribute to accelerated ROS generation and oxidative damage during aging.
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kuka
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Tatarkova
authors.forename: Peter
authors.initials: P
authors.lastname: Racay
authors.forename: Jan
authors.initials: J
authors.lastname: Lehotsky
authors.forename: Dusan
authors.initials: D
authors.lastname: Dobrota
authors.forename: Peter
authors.initials: P
authors.lastname: Kaplan
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D015227:Lipid Peroxidation; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species